Present power switching contacts are composites of silver and cadmium oxide, the former for electrical conductivity, the latter to reduce the probability that the contacts will weld together. Although such materials give fully satisfactory performance, the potential of environmental restriction on fabrication has stimulated a search for alternatives. Of all potential candidates the most attractive material system is Ag-SnO.sub.2. However, such materials have been found to be excessively susceptible to cracking under the thermal stress imposed by switching arcs.
One approach to deal with this problem is to introduce an additive that reduces the surface energy and enhances the wetting by molten silver, thereby reducing the rate at which surface cracks propagate into the bulk. This approach has been the basis for the so-called matrix-strengthening effect in Ag-SnO.sub.2 system as well.
However, the approach of the present invention is to increase the compact strength by improving the bonding between silver and oxide particles, thereby reducing the tendency of cracks to form in the first place.